package com.clstu.map;

import java.util.Properties;

public class Properties_ {
    public static void main(String[] args) {
        Properties properties = new Properties();
        //properties.put("abc",null);
        //properties.put(null,"abc");//k-v都不能为null
        properties.put("jack",100);
        properties.put("john",100);
        properties.put("lic",100);
        properties.put("lic",90);//改变值
        System.out.println(properties);
        properties.remove("lic");
        System.out.println(properties.get("jack"));
        System.out.println(properties);
    }
}
